I have used it as a standalone DAC and a DAC/preamp. For the money, it is excellent in that regard. I have tried headphones, but I don't have good enough ones to judge.

Your timing is perfect. I'm in the process of researching headphones. I have been checking out the ones on Acoustics Sounds. There are virtually no retailers in my area that carry high end headphones. They can order them, but there are none to listen to and compare. I would greatly appreciate your opinion on which headphones to focus on. I'm not concerned about price.